Fruit juices found to support immunity without causing weight gain

13 Mar 2024 --- A new European study reveals that drinking 100% fruit juice has a negligible impact on daily calories but accounts for up to a quarter of children’s vitamin C intake and is an important source of other vital nutrients.

Some policymakers and researchers warn that regularly consuming fruit juices could lead to weight gain due to the natural sugar content. But, according to the study of European countries, fruit juices only contribute up to 14% of free sugar in people’s daily diets, compared with up to 92% from products containing added sugar, such as soft drinks, biscuits, sweets, chocolate and cakes.

Meanwhile, fruit juices account for up to 26% of children’s vitamin C intake and up to 19% of adults’ vitamin C intake. They also contribute up to 4% of daily potassium, which supports normal blood pressure, and provide up to 7% of the daily intake of folate, which supports a healthy pregnancy.

The study’s lead author, Dr. Janette Walton from Munster Technological University in Cork, Ireland, says: “Fruit juice is a major contributor to vitamin C intakes in children and adults. Given that too few people eat the recommended 5-a-day fruit and vegetables, fruit juice is a convenient and nutritious food in the diet.”

Inside the juice
Published in the journal Nutrition Research Reviews, the new analysis of national dietary surveys across 14 European countries for which data were available found that people who drink fruit juice consume on average just 137 g per day, lower than the recommended serving size of 150–200 ml that exists in some countries.

This equated to just 20–40 kcal per day, or 1-2% of a child’s or adult’s average daily energy intake, which would not be expected to have an impact on body weight.Fruit juices are sometimes dismissed due to their sugar content, but the study suggests they are beneficial to immunity and barely impact weight gain.

In contrast, the average daily serving of 100% fruit juice across each age group across Europe was enough to make a significant contribution to daily intakes of vitamin C, which is vital for immune function and boosts iron absorption.

The study found that fruit juice was responsible for 4-20% of daily vitamin C intake in infants, 6-26% in children, 8-20% in teenagers, 8-19% in adults and 6-19% in older adults.

The researchers also found that fruit juice accounted for 2–4% of daily potassium, which supports normal blood pressure and has been found to be lacking in people’s diets, according to the European Food Safety Authority.

Natural sugars
Meanwhile, the natural sugar in 100% fruit juices, which comes entirely from the fruit, contributed to just 2–14% of free sugar in people’s daily diets, compared with 48–92%, which is estimated to come from “optional” products containing added sugar.

Unlike sodas, nectars or other drinks, 100% fruit juices never contain added sugars and cannot be diluted with water under European law. 

Dr. Walton adds: “Our findings showed only a modest contribution of fruit juice to free sugars. In contrast, a recent review found that sweet foods and drinks with added sugars are the major sources of added sugars across Europe, contributing half to more than 90% of intakes.”

“This highlights the importance of targeting sugar reduction strategies for discretionary or ‘top-shelf’ foods, which are not recommended in food-based dietary guidelines. Unlike fruit juice, whose composition is controlled by law, these types of products can be legally reformulated to reduce their sugar content.”

More broadly, the study authors highlighted the lack of data on 100% fruit juice consumption in many countries in Europe, such as Germany, which they said makes it difficult to set Europe-wide policies without an accurate view of normal consumption levels.

Edited by Joshua Poole